Computed Tomography Department Research Articles

Infection prevention and control in CT Part 2: Radiographers' and radiology nurses' perceptions of high-risk scenarios contributing to non-adherence to IPC protocols

IntroductionAdherence to standard and transmission-based precautions in the computed tomography (CT) setting is central to effective infection prevention and control (IPC), yet there is limited evidence about medical imaging (MI) professionals' self-reported predictors of IPC breaches. This is the second of a two-part series on IPC in the CT setting. Part 1 reported on Australian baseline data relating to intravenous contrast media administration and power injectors. Part 2 presents Australian radiographers' and radiology nurses' perceptions of clinical situations that reduce adherence to standard and transmission-based precautions in CT. MethodsA self-administered survey was distributed to Australian radiographers and radiology nurses working in CT. Responses to an open-ended question “If I was to not adhere to the standard and transmission-based precautions in the CT department, it is most likely when …” was analysed using inductive coding for themes, followed by deductive analysis mapped to the Systems Engineering Initiative for Patient Safety (SEIPS) model. ResultsStudy participants (n = 136) were radiographers (n = 119; 87.5%) and nurses (n = 17; 12.5%). ‘Four themes were derived from the inductive analysis: (1) high-risk working conditions, (2) compliance with good practice, (3) attitudes and practice, and (4) quality of communication. Deductive analysis, using the SEIPS domains revealed that predominant issues related to ‘Tasks’ (43.7%) and ‘Organisation’ (30.6%) followed by issues related to ‘Person’ (16.9%), ‘Tools and technology’ (6.9%) and ‘Environment’ (1.9%). ConclusionMulti-faceted pressures on radiology staff may compromise adherence to standard and transmission-based precautions in CT. Task difficulty, time pressures whilst undertaking tasks, and reduced staffing could lead to lower adherence to standard and transmission-based precautions. Implications for practiceFuture studies that focus on evaluation of ‘Tasks’ and ‘Organisation’ domains of the SEIPS model may provide further insights to non-adherence behaviours in MI.

Availability of CT, MRI, and endoscopy procedures for Polish individuals with morbid obesity: cross-sectional telephone survey study.

The rise in morbid obesity presents diagnostic challenges in computed tomography (CT), magnetic resonance imaging (MRI), and endoscopy. Research on the availability of these procedures for people with extreme obesity is limited. We aimed to analyse the accessibility of CT, MRI, and endoscopy procedures for people with extreme obesity in a significant sample of facilities serving in the Polish public healthcare system. A telephone-based survey was conducted on healthcare facilities offering CT, MRI, or endoscopy procedures, identified using the Polish National Health Fund (NFZ) API. A refined questionnaire was utilized after a pilot study to collect details on the equipment's weight and diameter capacities, among other parameters. Of the initial 312 facilities sampled, 195 were eligible and successfully contacted, representing 9.4% of the facilities offering the procedures in the NFZ database. Of the 195 facilities, 86.4% of CT departments knew their scanner's maximum weight, 57.6% its diameter; 76.5% of MRI departments recognized their scanner's weight, and 59.2% its diameter, while 77.3% of endoscopy departments were aware of their maximum weight capacity. Approximately 28% of CT, 5% of MRI, and 39% of endoscopy departments could perform the procedure if the patient's weight was over 200 kg. Facilities knowledgeable about CT's maximum diameter and MRI's maximum weight often provided private CT/MRI services. A significant proportion of Polish facilities providing CT, MRI, and endoscopic examinations in the Polish public healthcare system were unaware of their equipment's weight and diameter limits. Merely 5% of the surveyed MRI facilities could potentially accommodate a patient weighing over 200 kg.

Diagnostic accuracy and prognostic value of lung ultrasound in coronavirus disease (COVID-19).

PurposeThis study aimed to assess the correlation between lung ultrasound (LUS) and computed tomography (CT) findings and the predictability of LUS scores to anticipate disease characteristics, lab data, clinical severity, and mortality in patients with COVID-19.Material and methodsFifty consecutive hospitalized PCR-confirmed COVID-19 patients who underwent chest CT scan and LUS on the first day of admission were enrolled. The LUS score was calculated based on the presence, severity, and distribution of parenchymal abnormalities in 14 regions.ResultsThe participants’ mean age was 54.60 ± 19.93 years, and 26 (52%) were female. All patients had CT and LUS findings typical of COVID-19. The mean value of CT and LUS severity scores were 11.80 ± 3.89 (ranging from 2 to 20) and 13.74 ± 6.43 (ranging from 1 to 29), respectively. The LUS score was significantly higher in females (p = 0.016), and patients with dyspnoea (p = 0.048), HTN (p = 0.034), immunodeficiency (p = 0.034), room air SpO2 ≤ 93 (p = 0.02), and pleural effusion (p = 0.036). LUS findings were strongly correlated with CT scan results regarding lesion type, distribution, and severity in a region-by-region fashion (92-100% agreement). An LUS score of 14 or higher was predictive of room air SpO2 ≤ 93 and ICU admission, while an LUS score ≥ 12 was predictive of death (p = 0.011, 0.023, and 0.003, respectively).ConclusionsOur results suggested that LUS can be used as a valuable tool for detecting COVID-19 pneumonia and determining high-risk hospitalized patients, helping to triage and stratify high-risk patients, which waives the need to undertake irradiating chest CT and reduces the burden of overworked CT department staff.

Common computed tomography artifact: source and avoidance

BackgroundArtifacts have significantly degraded the quality of computed tomography (CT) images, to the extent of making them unusable for diagnosis. The types of artifact that could be used are as follows: (a) streaking, which is commonly due to a discrepancy in a single measurement, (b) shading, which is due to a group of channels deviating gradually from the true measurement, (c) rings, which are due to errors in individual detector calibration and (d) distortion, which is due to helical reconstruction. It is occasionally possible to avoid scanning of a bony area, by means of changing the postion of the patient. Thus, this study aimed to evaluate the common artifacts that affect image quality and the method of correction to improve image quality.ResultsThe data were collected by distributing a questionnaire to the CT technologist at different hospitals about the most common type of artifacts in the CT images, source of artifacts and methods of correction. A total of 95 CT technologists responded to the questionnaire, which included 67% males and 33% females. Most of the participants (70%) were experienced CT technologists, and 61% of the participants had not done any subspecialty CT scan courses. The most common artifact used in the CT departments was motion artifact in brain CT (73%), and the best method to reduce motion artifact was patient preparation (87%).ConclusionsThe most common shown artifact in this study was motion artifact, and the common cause was the patient-based artifact. It is important to understand why objects occur and how they could be prevented or suppressed to improve image quality.

PEDIATRIC REGIONAL DRL ASSESSMENT IN COMMON CT EXAMINATIONS FOR MEDICAL EXPOSURE OPTIMIZATION IN TEHRAN, IRAN.

The main purpose of this pilot study was to assess the regional diagnostic reference level (RDRL) of computed tomography (CT) examinations to optimise medical exposure in five pediatric medical imaging centers in Tehran, Iran where the most frequent CT examinations were investigated. For each patient, CT volume dose indexes (CTDIvol) and dose length product (DLP) in each group were recorded and their third quartile was calculated and set as RDRL. Pediatrics were divided into four age groups (<1; 1-5; 5-10 and 10-15years). Then, the third quartile values for head, chest and abdomen-pelvic CTs were, respectively, calculated for each group in terms of CTDIvol: 21.3, 24.4, 24.2 and 36.3mGy; 2.9, 3.2, 3.7 and 5.7mGy; 3.7, 5.7, 6.3 and 6.8mGy; and in terms of DLP: 322.2, 390.1, 424.9 and 694.1mGy.cm; 53.1, 115.2, 145.3 and 167.6mGy.cm and 128.7, 317.7, 460.2 and 813.8mGy.cm. Finally, RDRLs were compared with other countries and preceding data in Iran. As a result, CTDIVOL values were lower than other national and international studies except for chest and abdomen-pelvic values obtained in Europe. Moreover, this matter applied to DLP so that other formerly reported values were higher than the present study but European values for chest and abdomen-pelvic scans and also Tehran studies conducted in 2012. Variation of scan parameters (tube voltage (kVp), tube current (mAs) and scan length), CTDIvol and DLP of different procedures among different age groups were statistically significant (P-value <0.05). The variations in dose between CT departments as well as between identical scanners suggest a large potential for optimization of examinations relative to which this study provides helpful data.

Carotid-Cavernous Fistula Presenting With Bilateral Abducens Palsy.

Carotid-Cavernous Fistula Presenting With Bilateral Abducens Palsy.

Computed Tomography Dose Reduction in Children: Review Paper

Increasing the needs of Computed Tomography (CT) for children is quietly augmented over the last decades, although it’s one of the most important modalities in diagnostic finalization. However, it carries a higher risk for the patient in term of radiation dose and cancer risk due to higher sensitivity to radiation than the adult. This study was conducted to review the multiple methods of dose reduction technique as presented by different authors where the different scanning protocols, machine and types of the studies were presented Here, more studies and books were selected, where they are carefully summarized and outlined into different categories for which the result stated that; the most frequent examination done in the CT department is head, neck, and sinuses in which where taken as an example of dose reduction methods. The use of the most modern technical advances was recommended in order to optimize the dose level, comfortable, constants (anesthesia if required) position and using low number of phases as possible according to the pathology of interest (low phases with better visualizations), scanning with thin collimation and view thicker as possible, increasing pitch, automatic exposure control, only the area of interest should be examined, with low tube voltage and using of tube current modulation system can give better result of dose reduction and there were multiple methods presented here. Where is most important for radiologist, technicians, and the person who conduct such studies to increase their knowledge in radiation protection, technical advances and how to interpret the different CT protocols.

Improving Language Service Access for Patients with Limited English Proficiency in the Outpatient CT Department

In the outpatient Computed Tomography (CT) imaging department at Sunnybrook Health Sciences Centre, patients with limited English proficiency (LEP) and healthcare providers often face significant challenges in communication during exams with contrast administration. While family members and bilingual staff can help interpret, there are concerns over patient confidentiality, accuracy of medical translation, and patient safety.

Importance of patient radiation protection in computed tomography procedures

The aim of the present work was to describe the importance of establishing a strong patient radiation protection program in computed tomography (CT) departments. Radiation protection in computed tomography (CT) deserves special attention since CT is the largest contributor to patient radiation exposure in diagnostic radiology. Radiation protection in CT examinations has been recommended by international organizations as well as AIEA program. As part of our proposals is the dose reduction in CT systems used, ALARA principle application and the enshrined the international guide regulations for the protection of patients were based on. For our staff working with ionizing radiation in CT departments is supervised under national authorities by legal limits but for patient radiation protection has not been involved in the national legislation.

P007] Patient dose management systems. Our experience in the CT department

Purpose Computed Tomography (CT) scanners are equipped with a vast variety of different technology and protocols. Due to the extended range of technical parameters (kV, mA, rotation time, pitch, filters, reconstruction algorithms, etc.), radiation dose varies significantly between patients. Depending on clinical needs and patient body habitus, patient radiation dose differs, even for the same anatomical region, clinical indication, technical protocol and even for the same CT. Thus, the need to monitor, optimize and generally review medical practices in CT has risen immensely. Manually dealing with these demanding tasks can be extremely time consuming. Nowadays, sophisticated patient dose management software (PDMS) with user-friendly interface can assist to this task, resulting in an easier and quicker way to monitor and analyse data. Our study focused on getting a general overview of the software capabilities, investigating potential difficulties or practical issues during use, evaluating staff performance in the daily routine and examining if and how the PDMS could assist in a more efficient management of the department. Materials and methods A commercially available PDMS (DOSE by Qaelum, Leuven, Belgium) was recently installed in our CT department. The software was connected to our 64-slice CT scanner. More than 6000 CT examinations were analysed. Volumetric Computed Tomography Dose Index (CTDIvol), Dose Length Product (DLP) and Effective Dose (E) were evaluated for chest, abdomen and chest-abdomen-pelvis exams. Organ doses estimated, by the software, were also evaluated. Results The software provided easy, quick statistical overview of clinical/technical data. Typical local doses were comparable to national/international data. Organ doses estimated proved to be a valuable tool in individualized patient dosimetry. It also provided the time periods the scanner was not in use and facilitated easy scheduling of routine quality control tests and other routine tasks. A number of errors were identified and communicated to the staff; corrective actions were taken. Conclusions The PDMS proved to be a highly sophisticated system and a valuable tool for managing the radiology department. It provided advanced analysis that could assist for an in-depth evaluation in terms of patient dosimetry, staff performance and usage of equipment.

Evaluation of some spiral and sequential computed tomography protocols of adults used in three hospitals in Shiraz, Iran with American College of Radiology and European Commission guidelines.

PurposeUse of computed tomography (CT) has increased considerably all over the world. In addition, there has been an increased demand for utilisation of CT scanning in Iran over the past decade, especially after introducing multi-detector computed tomography (MDCT). It should be considered that making a mistake in the selection of scan parameters leads to patients receiving higher doses and having increased risk of cancer. All of these facts prompted us to compare six routine CT protocols in three hospitals in the city of Shiraz, and to compare the results with American College of Radiology (ACR) practice parameters and European Commission (EC) guidelines for dual- and multi-detector CT.Material and methodsIn the studied hospitals, 10 adult patients were chosen randomly for every six protocols, taken by different technologists. Seven and 11 scan factors in sequential and spiral scans, respectively, were compared with ACR (2014) and EC guidelines (EC16262 & EC2004).ResultsThe majority of scan factors in sequential and the spiral protocols that were scrutinised met the guidelines. The CTDIvol and DLPs for sequential and spiral scans were lower than the dose reference level (DRL) pronounced by ACR in three CT departments, and they were compatible with the recommended dose by EC (16262) in a private hospital.ConclusionsBased on accordance of CTDIvol with ACR measurements and incompatibility with EC (2004) in teaching hospitals, we concluded that the recorded doses should be compared with different criteria. A regular review of protocols, using special protocols for different pathologic circumstances and continual education for technologists in the three CT departments, are recommended.

Scheduling appointments for multiple classes of patients in presence of unscheduled arrivals: Case study of a CT department

Appointment scheduling plays a key role in improving the performance of a healthcare facility and increasing patient access to health care. However, appointment systems in hospitals may receive requests for services from walk-ins and emergency arrivals in addition to the scheduled arrivals. Emergency arrivals need urgent care, and hence have higher priority to be served over the scheduled arrivals. Such emergency arrivals disrupt the scheduled appointments, and may increase the waiting times of scheduled patients and the overtime of the appointment session. Walk-ins have lower priority to be served. However, it is desirable to serve walk-ins in order to increase the utilization of the server keeping the waiting times of scheduled patients as short as possible. In this research work, appropriate sequencing and appointment rules are identified for a computed tomography (CT) scan facility that experiences walk-in and emergency arrivals apart from regular scheduled arrivals. Several scheduling rules are evaluated under different patterns of walk-ins and emergency arrivals. In addition, the main and interaction effects of scheduling rules and arrival patterns of unscheduled patients are explored. It is found that the scheduling rules are more influential than the arrival patterns of unscheduled patients.

Ranking and Evaluating CT Departments by Quality Function Deployment

Rankings have a great value in providing necessary information to take the appropriate decision in various fields. In the healthcare sector, ranking systems have a vital and important role in the development of each hospital. The aim of this paper is to design mathematical ranking model based on quantitative parameters and sub parameters using quality function deployment to rank the computed tomography (CT) departments in hospitals. The proposed model is based on parameters extracted from both the hospitals and the CT scan devices. The output of the system from 30 different hospitals has been compared with experts’ opinions showing an average error of 2.04 % ±1.9%.

Patient-journey modelling and simulation in computed tomography

Purpose – The purpose of this paper is to present a business process reengineering (BPR) framework of process and data integration with patient journey as the basis for process evaluation and the improvement of patient-flow. Design/methodology/approach – A BPR framework is developed using a mixed-method research design, which incorporated a case study to demonstrate a healthcare scenario with associated processes and data elements, using process models based on event-driven process chain methodology as well as patient and data models, based on unitary structuring technique. The framework includes key processes including patient booking and rebooking, and associated inputs, outputs, and control parameters. In this case, the framework is demonstrated through application to computed tomography (CT) services in a hospital to improve patient-flow, with numerical simulation of CT data collected over time. Findings – The framework supports flexible patient scheduling and the associated planning of healthcare operations and logistics – this in turn helps to improve patient-flow. Furthermore, mathematical modelling and simulation precisely reveal the impact of booking and rebooking on the performance of the CT department. Research limitations/implications – This innovative framework has potential value for other services, within and beyond the hospital setting. Originality/value – The proposed framework of process modelling, data, and patient journey addresses the lack of a holistic approach to monitoring and evaluating service performance in hospital settings. Patient journey modelling is an integral part of process and data models that can be implemented in an integrated system environment such as an enterprise resource planning system for real-time monitoring of patient-flow under dynamic conditions.

Ranking and Evaluating CT Departments by Fuzzy Logic

Rankings approaches are a public way of providing information in different fields. In health care domain, the direct impact of the ranking systems is that these hospitals will explore all the paths to improve their rank that reflect on attracting more patients. Current methodologies mainly include subjective indicators in their ranking systems. The purpose of this paper is to develop a new quantitative ranking model based on multi-criteria decision making using fuzzy logic to rank the computed tomography (CT) departments in hospitals. The system is based on factors extracted from both the hospitals and the CT scan devices. The output of the system from 30 different hospitals has been compared with experts’ opinions showing an average error of 2.17 ±1.8.

Establishment of diagnostic reference levels in computed tomography for paediatric patients in Sudan: a pilot study.

Paediatric patients are recognised to be at higher risk of developing radiation-induced cancer than adults. The purpose of this pilot study was to evaluate the radiation doses to paediatric patients during computed tomography (CT) procedures in order to propose local diagnostic reference levels (DRLs). A total of 296 patients (aged 6-10 y) were investigated in 8 hospitals equipped with 64-, 16- and dual-slice CT machines. The mean dose length product values were 772, 446 and 178 mGy cm for head, abdomen and chest, respectively. Imaging protocols were not adapted to the patient's weight in certain CT machines. The results confirmed that paediatric patients are exposed to an unnecessary radiation dose. The established DRLs were higher than those available in other countries. This study showed the need for harmonisation of the practice in CT departments and radiation dose optimisation.

The establishment of computed tomography diagnostic reference levels in Portugal

The aims of this study were to investigate the frequency of Portuguese computed tomography (CT) examinations, identify protocol application and establish diagnostic reference levels (DRLs). CT departments (n=211) were surveyed nationally (June 2011-January 2012) and CT protocol information and dose data were collected, as were retrospective age-categorised paediatric CT data from three national paediatric centres. The proposed national CT DRLs (CTDIvol) for adults were 75, 18, 14, 18, 17, 36, 22, 27 and 16 mGy for head, neck, chest, abdomen, pelvis, cervical, dorsal, lumbar and joints, respectively. The levels for paediatric head and chest examinations were as follows: 48 and 2 mGy (newborns), 50 and 6 mGy (5 y olds), 70 and 6 mGy (10 y olds) and 72 and 7 mGy (15 y olds). A limited number of current paediatric protocols aligned to recommended international age categorisations. Portuguese DRLs were generally higher than European recommendations, suggesting potential for optimisation. The need for greater standardisation of age-categorised paediatric protocols was identified.

Drainage of Post-Operative Abdominal and Pelvic Abscesses Under the Guidance of Computed Tomography

BACKGROUND: Cross sectional imaging and specifically computed tomography (CT) has become the main radiological modality of detecting post-surgical abdominal collections and abscesses. Percutaneous abscess drainage (PAD) has revolutionized the treatment of abscesses, especially of post-surgical abdominal abscesses over the last 25 years; repeat laparotomy is a rare event due to the fact that the success rate of PAD is very high (90-95%) and complications are few (0-10%). OBJECTIVE: The aim of the study is to present our experience in the department of computed tomography of the percutaneous drainage of post-operative abdominal and pelvic abscesses. PATIENTS AND METHODS: During the last two and a half years, 93 post-operative patients were referred to the CT department for drainage of a post-surgical abscess in the abdomen or pelvis at 9-21 days post-operatively due to persistent fever. A total of 95 abscesses were drained; 84 were located in the abdomen and 11 in the pelvis. Abscess diameters ranged between 2 and 12 cm. A percutaneous drainage technique under CT-guidance was employed in all patients; 98 catheters were placed with use of the Seldinger technique. A transgluteal paracoccygeal approach was adopted in 11 patients. Aspiration of an intra-loop abscess was performed in 1 patient. The tilted gantry technique was utilized in 2 cases. RESULTS: Eighty-nine (95.7%) patients were successfully treated. In 4 (4.3%) patients the abscesses were partially drained, patients were stabilized and subsequently treated via laparotomy. Complications included inflammation of the skin at the entry site in 4 patients, pneumothorax in 1 patient, and displacement of the catheter in 12 patients, one involving catheter migration into the duodenum. Major complications did not occur. CONCLUSION: Percutaneous drainage of post-operative abdominal and pelvic abscesses was a safe and effective method of abscess management in our series with a 95.7% success rate and absent major complications. It is currently a widely used procedure, eliminating the need for repeat laparotomy in the majority of patients. Proper catheter management is essential for the successful outcome.

Value of multislice computed tomography in the diagnosis of acute mesenteric ischemia

To define the value of multislice computed tomography (CT) in the diagnosis of acute mesenteric ischemia (AMI). Two hundred patients (age range: 20-92 years) who were referred to the emergency CT department with a clinical suspicion of AMI were prospectively included in the study. CT examinations were performed with a multislice (16) CT scanner and the protocol included pre-contrast, arterial and venous phase acquisitions. Images were evaluated by using multiplanar reconstruction, maximum intensity projection and volume-rendering techniques at the CT workstation. Ninety-four patients (47%) underwent surgery for AMI or for other causes of acute abdominal pain. One hundred-six patients (53%) were followed conservatively according to clinical, radiologic and laboratory findings. Of the 94 patients who underwent surgery, 49 (25%) were found to have AMI. All of these 49 patients with a proven AMI diagnosis were diagnosed with CT. In the other 45 patients who underwent surgery, CT findings were negative for AMI. None of the patients, who were followed conservatively, were eventually diagnosed as having AMI except 1 patient. This patient was unfit for surgery although his clinical and radiologic findings were consistent with AMI and died in 3 days. The sensitivity and specificity values of CT for the detection of AMI were calculated to be 100% for each. Multislice CT is an effective imaging technique for the diagnosis of AMI with excellent sensitivity and specificity values.

Low dose of rectal thiopental sodium for pediatric sedation in spiral computed tomography study

The aim of this study was to determine the effectiveness of reduced new dose in rectal sedation by thiopental sodium for computed tomography (CT) diagnostic imaging. A total of 90 children (mean age, 24.21 month +/- 13.63 [standard deviation]) underwent spiral CT study after rectal administration of thiopental sodium injection solution. The new dose ranged from 15 to 25 mg/kg with a total dose of 350 mg. The percentage of success and adverse reaction were evaluated. Sedation was successful in 98% of infants and children with an average time of 8.04 min +/- 6.87 (standard deviation). One of the cases found desaturation, two experienced vomiting, 14 found rectal defecation, and two experienced hyperactivity. No prolonged sedation was observed. Rectal administration of thiopental sodium for pediatric CT imaging is safe and effective even for hyperextend position by new reduced dose of the drug. This procedure could be easily done in the CT department under supervision of the radiologist.